1. Field of the Invention
This invention relates to a software use method control system for controlling a method of using software.
2. Description of the Related Art
Recently, personal computers (hereinafter abbreviated as "PCs") have become increasingly used. In accordance with this trend, more and more software items, such as electronic books and digital video movies, have become increasingly accessible through PCs, in addition to video games and business-related software. Furthermore, software items prepared by individuals are distributed in increasing numbers.
In view of this trend it is essential to protect copyrights pertaining to software items. Various methods have been devised to prevent illegal use of software.
One of the copyright-protecting methods is to employ a system architecture called "super-current architecture." Super-current architecture is a system which is designed to levy charges on the use of software, to give permission to use software upon payment of the charges, and to determine whether or not to permit the use of software in accordance with various conditions under which the software will be utilized.
Owners of software may use any data item contained in the software as a reference, may revise or edit the software in part or wholly, may copy and distribute the software in part or wholly--only in the specific manner which the copyright owner has designated. A software use method control system has yet to be developed, however, which can prohibit the software owners from exploiting the software in any manner other than the designated manners.
Such a software use method control system may be provided in the form of a special operating system (abbreviated as "OS") or a program that can be executed on an OS. It is difficult to devise a control system of this type, simply because software can be used in countless ways, whatever kind it is. For the copyright owner it is impossible to predict every way in which the software owners may exploit the software, in an effort to design a software use method control system which can prohibit the software owners from exploiting the software in any possible manner other than those designated by the copyright owner.
The copyright owner may revise the software use method control system every time he or she thinks of new ways in which the software owners may utilize the software but which are prohibited by the copyright owner. For the copyright owner it is difficult to modify the control system so often since a great cost is required to do so. Even if the copyright owner can afford to and does modify the software use method control system as frequently as needed, there are problems on the part of the copyright owner.
A variety of OSs have been developed for use in PCs which are now used in increasing numbers. Each of these OSs can be applied to many different programs, each reflecting the originality of the programmer. Therefore, a plurality of OSs, for example a first OS and a second OS, can be executed on the same PC which is designed to execute a particular software use method control system. The PC user has access to system resources of either OS. Thus, he or she can get a system resource from the second OS, though unable to obtain the identical protected system resource from the first OS. In other words, the PC user can illegally acquire a system resource from the second OS, which is protected in the first OS. Further, the PC user can acquire any protected system resource of the first OS from the second OS, can modify the protected system resource and can, thereafter, make unauthorized access to the protected resource of the first OS. Still further, malfunction of the first OS, if it occurs, destroys the protected system resource which corresponds to any system resource of the second OS.
A PC user may use any existing OS, thereby acquiring the right to access the system resources of the OS. Then, he or she can gain unauthorized access to any system resource, not only one not protected, but also one protected by a software use method control system. Also he or she can achieve unauthorized access to the protected system resources corresponding to all programs being executed on the OS, by making use of the right to access the system resources of the OS.
In order to operate a software use method control system of the above-described type on a programmable system such as a PC, it is necessary to protect system resources from unauthorized access. In the existing OS circumstances, however, it is impossible to protect system resources though they should be protected by means of a software use method control system.
To develop a software use method control system in the form of a special OS, it is necessary to develop novel circumstances in which to prepare and use software. The cost of developing the control system is huge. In addition, it is very hard to attract PC users to the newly developed OS, away from an existing OS, if any, which is predominant on the market.
Instead of attempting to develop a full-scale software use method control system, an OS of minimum scale, having a structure of a software use method control system, may first be designed and used to control an existing OS, thereby to utilize the features of the existing OS in which to prepare and use software. To utilize the existing OS features, some program items must be transplanted to the existing OS. Here arises a problem. The copyright owner of the existing OS may not permit the software use method control system developer to transplant the program. If the owner permits the control system developer to do so, he or she will likely demand a huge royalty of the control system developer.
The problems with the conventional software use method control systems, which have been discussed, can be summarized as follows:
(1) The software use method control system cannot prohibit software owners from exploiting the software in any manner other than those designated by the owner of the copyright to the software.
(2) Since software can be used in countless ways which can hardly be predicted, a software use method control system can hardly be designed which can prohibit the use of software in every possible way other than that which the copyright owner has designated. The copyright owner may revise the control system every time he or she thinks of new ways in which software owners may exploit the software illegally, but cannot afford to revise the control system so often since a great cost is required to do so.
(3) To operate the software use method control system of the above-described type on a programmable system such as a PC, the system resources must be protected from unauthorized access. The system resources of the control system cannot be protected in S the existing OS circumstances, however. They cannot be protected in the ordinary multi-OS circumstances, either.
(4) The software use method control system may be developed in the form of a special OS. In this case, novel circumstances in which to prepare and use software need to be developed, as well. The cost of developing the control system is inevitably huge.
(5) An OS of minimum scale, having a structure of a software use method control system may first be designed and used to control the conventional OS, thereby to utilize the circumstances of the existing OS in which to prepare and use software. To utilize the existing OS circumstances, some program items must be transplanted to the existing OS. However, the copyright owner of the existing OS is likely not to permit the program transplantation. If the owner permits the program transplantation, a huge royalty must be paid to the copyright owner.